1. Field of the Invention
The present invention relates to an endoscope cover type endoscope apparatus which uses an endoscope to be covered by inserting the endoscope to be covered into an endoscope cover.
2. Description of the Related Art
Recently, endoscopes have been widely used in the field of medical treatment. When an endoscope used in the field of medical treatment is inserted into a living body, an observation window provided at the tip of an-insertion tube is sometimes soiled by bodily fluid, so that the endoscope cannot clearly observe the inside of the living body. Therefore, an endoscope is provided with air supplying and water supplying functions so as to be able to wash the observation window by spraying the observation window with water and to blow excess water off by supplying air from the proximal portion of the endoscope. Further, the supplying air function can also be used in a case in which air is supplied to the body cavity to observe an observation portion easily. The air and water are supplied through an air supplying channel and water supplying channel.
Further, the endoscope is provided with a forceps channel (treatment tool channel) so as to be able to collect tissues by means of biopsy forceps or to be able to give treatment using treatment tools.
In an endoscope used in such a medical treatment field, an endoscope used once for a patient is washed or disinfected to prevent infection. However, it takes time to wash and disinfect it completely. Thus, the maneuverability of the endoscope is low and also, use efficiency of the endoscope is lowered.
Especially, each of the aforesaid channels was connected to the outside of a living body through a channel from a tip opening portion which opened into the body cavity of a patient, so that it was troublesome to completely wash and disinfect the tip opening portion and the inside of the channel.
Therefore, recently, what is known as a cover type endoscope has been adopted. In the cover type endoscope, an endoscope itself is covered with an endoscope cover and the endoscope cover is thrown away in each and every treatment to simplify the washing and disinfection after use.
By use of the cover type endoscope, even in an expensive video endoscope using illumination means and a solid state imaging device (SID), a channel which opens into the body cavity of a patient is provided in the aforesaid endoscope cover so that the observation means and illumination means which do not open into the body cavity are provided in the endoscope, and are covered with an endoscope cover. Thus, the video endoscope does not become unclean after use and also, washing and disinfecting can be simplified by throwing the endoscope cover away.
Such a cover type endoscope is disclosed, for example, in U.S. Pat. No. 4,646,722 and No. 3,162,190.
As shown in FIG. 1, in such a cover type endoscope, a catching groove 103 is formed on the inner periphery of a connector for fixing endoscope operation part 102 provided on the upper portion of an endoscope cover 101 and an engaging portion 105 engaged with the catching groove 103 is formed on the outer periphery of an endoscope to be covered 104 to be inserted into the catching groove 103. Therefore, the endoscope cover 101 is fixed on the endoscope to be covered 104.
The length of the insertion tube 104a of the aforesaid endoscope to be covered 104 is determined in every purpose and affected part to be used. If the length of the insertion tube 104 changes, the endoscope cover 101 for covering should be selected in accordance with the endoscope to be covered 104 which is used, as well.
That is, when the length of an insertion tube 104a of the endoscope to be covered 104 is shorter than the length of an insertion tube 101a of the endoscope cover 101, an opening is made between the tip of the insertion tube 104a and the tip of the insertion tube 101a of the endoscope cover 101. Thus, a close-up area cannot be observed. Then, illuminating light is reflected in a cover lens of the endoscope cover 101 and enters an observation optical system and then causes inconvenient optical effects, such as flare.
On the other hand, if the length of the insertion tube 104a of the endoscope to be covered 104 is longer than the length of the insertion tube 101a of the endoscope cover 101, the catching groove 103 of the endoscope 101 will not be engaged with the engaging portion 105 of the endoscope to be covered 104, so that the endoscope cover 101 cannot be fixed to the endoscope to be covered 104.
Therefore, the endoscope cover 101 applied to the endoscope to be covered 104 had to be selected conventionally. Not only the preparatory operation takes time but also many kinds of endoscope covers 101 should be previously prepared. Thus, the preparation was time-consuming.
In addition, even for the same purpose, it is technically difficult to produce the endoscope to be covered 104 and endoscope cover 101 having the same length. The aforesaid problem is also made by an uneven common difference between the endoscope to be covered 104 and endoscope cover 101 which are used for the same purpose.
The operation for fitting the endoscope cover to the endoscope to be covered is sometimes performed on an endoscope cover tray which is kept clean. Such an endoscope to be covered has a structure in which an insertion tube to be inserted into the body cavity, and a connecting cord portion having a connector connected to external devices such as a light source and video processor are arranged in an L shape and the connecting cord portion does not become an obstacle when the endoscope is operated at an operation part provided in a proximal portion of the aforesaid insertion tube.
However, if the aforesaid insertion tube and connecting cord portion are arranged in an L shape, the endoscope cover fitted to the endoscope to be covered should be subdivided into the insertion tube, operation part and connecting cord portion of the endoscope to be covered, respectively. Therefore, it is troublesome to fit the cover to them and maneuverability is low.
If the aforesaid endoscope to be covered is formed in an L shape, a shape of an endoscope cover tray which is used when the endoscope to be covered is fitted to the endoscope cover should be an L shape. Since the formation of an L shaped tray for an endoscope cover makes the volumetric efficiency of the tray worse, there is a problem in housing capacity and handling capacity.
Further, as mentioned above, an endoscope used as the endoscope of a cover type (temporally called as "endoscope to be covered") is not provided with sucking channel, supplying air channel and supplying water channel. Each of these channels is provided in an endoscope cover and exchanged in every treatment.
Accordingly, the shape of the external connecting portion of the endoscope to be covered can be smaller and lighter than the outer connecting portion of a general coverless endoscope by the portion in which the aforesaid channels are not provided.
If the external connecting portion of an endoscope to be covered becomes smaller and lighter, an endoscope to be covered can be easily handled. Additionally, an external device, such as a light source device for connecting the external connecting portion can be smaller.
However, if the shape of the external connecting portion is different from that of a general coverless endoscope, the interchangeability for a controlling device such as a light source and video processor which are the external devices of the coverless endoscope is lost, so that a user has to equip the aforesaid external devices when the endoscope to be covered is used and that the user is forced to pay the expense of the equipment.